Single/multi-band Wilkinson-type power dividers with embedded transversal filtering sections and application to channelized filters

This paper addresses the exploitation of signal-interference concepts for the realization of single/multi-frequency Wilkinson-type filtering power dividers in planar/lumped-element technologies. By embedding transversal signal-interference filtering sections into the arms of conventional Wilkinson-type power-divider topologies, RF/microwave power-distribution actions with intrinsic mono/multi-band bandpass filtering capabilities can be obtained. Analytical equations and rules for the theoretical synthesis of this dual-function device are derived. The generalization of the approach to multi-stage schemes for enhanced-performance designs or for the shaping of frequency-asymmetrical responses is also discussed. Furthermore, for practical demonstration, three prototypes are developed and characterized. They are a microstrip quad-band circuit for the 1-5 GHz range, a dual-band lumped-element device for the band of 0.2-0.6 GHz, and a new type of two-branch channelized active bandpass filter at 3 GHz that makes use of single-band versions of this dual-behavior component as signal-division/combination blocks.